Internal-combustion motor



March 26, 1929. M. w. HALL 1,707,005 INTERNAL COMBUSTION MOTOR I FiledJn. 8, 1927 s sheets-sheet 1 ATTORNEY March 26, 1929. M. w. HALL1,707,005

INTERNAL COMBUSTIN MOTR Filed Jan. 8'1927 3 Sheets-Sheet 2 QNTLOO, NmOolw l E March 26, 1929. M, w. HALL 1,701,005

INTERNAL COMBUSTION MOTOR Filed Jan. s, 1927 5 sheets-snee; 5

INVENTOR. l @n Ada/z WHczl BY ATTORNEY lll Patented Mar. 26, 1929.,

UNITED STATES 1,707,005 ra'lulifrjv oF-FICE.

MILAN w. HALL, or NEW aocHELLE, NEW Yomr; mNE'rrA HALL, ADMINISTRATRIXor SAID MILAN W. HALL, nEoEAsED, AssIGNon To EDWIN B. lLarnAit, or

HOBOKEN, NEW JERSEY. Y

INTERNAL-counussrroN Moron.

YMy invention relates to internal combustion motorsand has for an objectto improve the thermal function ot compression in such motors,particularly when operating at reduced loads.

In pre-mixture type internal combustion motors, such as are inV generaluse today, the compression stroke of the piston and the combustion spacein the cylinder are fixed and the motor is lcontrolled by a throttlewhich attenuates the fuel charge tor lighter loads. The volume of thecombustion space is limited by the fact that when the throttle is wideopen for Jnll loads, the tuelmust not be compressed above the criticalpressure at which spontaneous combustion takes place, with the resultthat when the motor is throttled down for light loads there isinsuliicient compression of the `Juel charge.

\ vide aninternal combustion motor of exceed' My invention aims toovercome thisdeficiency of ordinary internal combustion motors byproviding means for varying the fuel charge volume Without attenuationat the beginning of the compression period and simultaneously varyingthe combustion space volume inaccordance with volumetric variations ofthe charge, whereby compressione-is maintained at constant or uniformpressure under all variations of load.

Another object of my invention is to improve the thermal function ofexpansion of? numeral 15 to indicate the cylinder blockof internalcombustion motors.

In the ordinary pre-mixture type of internal combustion motors, the`expansion period of the piston is approximately equal to thecompression period, whereas forlideal thermal efficiency, expansion ofthe ignited gases shouldl far exceed theirlcompression. My inventionaims to provide a motor in which the expansion of the gases ofcombustion may be set at any desired ratio.

Another object of my invention is to proingly simple lconstruction whichrequires no throttle valve, poppet valves, nor sleeve 1 claims.-

With these and other objects inf view my 1nvention consists in certainnovel 'features of construction and combinations and arrangements otparts, which will be more fully hereinafter described and I In theaccompanying drawings,

Figure 1 is a view, in transverse vertical section, of' an internalcombustion motor ernbodying my invention;

pointed out in the I Fig. 2 is a side view of a portion of the motor,shown largely in section;

' F ig. 3 is a side view partly broken away, of a detail of myinvention;

Figs. 4 and 5 are views in horizontal sectiontaken on the lines 4 4: and5-5 respectively, of Fig.I l.;

Fig. 6 is a crank cycle diagram of the twostroke piston of my motor;

Fig. 7 is a crank cycle diagram ofthe Jour-` stroke piston of my motor;and

Figs. 8 to' 12 inclusive, are schematic views showing the relativepositions of the :tourstroke and two-stroke pistons when operating atfull load at the positions of ignition, open- Ying of the exhaust,closing of the exhaust,

opening of the intake, andiclosing of `the intake, respectively, thecorresponding lpositions of the pistons when set for light load, beingindicated in the figures by dotted lines.

In the drawings I have used the reference ciprocate in the upper portionof the c l-g inders. The cylinder blockisprovided with the usual waterjacket 19 which surrounds that portion of the cylinders in which themain pistons reciprocate and also the Alower part of that portion of thecylinders in which the auxiliarypistons reciprocate. VThe lower part ofthecylinderblck is formed with the 'usual crank case 20 in whichismounted a crank 'shaft 21 connected to the pistons 17 by means of`connecting rods 22. vAt the upper 'end of the cylinder blockthere isanother the four-stroke cycle and pistons 18 o1. the two-stroke cycleand hence the crank shafts 21 and 24 are connected by reduction gearing,such that lthe lattercrank shaft shall run at half the speed of theformer crank shaft. This gearing includes means for varying the relativeangular position of the crank shaft 24 with respect to the crank shaft21. To this end a spirally toothed wheel 26 is keyedto one'end ofthecrank shaft 24. .Mounted to rotate freely on the crank shaft 24/isanother wheel 27 which is formed with a laterally extending rimperipherally surrounding but spaced from the wheel 26. The innerperiphery of the rim 27 is formed with spiral teeth whose pitch or angleis reversed with respect to the spiral teeth on the wheel 26.' Mountedto slide on the shaft 24 is a sleeve 28 which has an eX- tension adaptedte' ht between the wheels 26 and 27. This sleeve provided on the innerperiphery of 'the extension with teeth adapted to engage the teeth ofwheel 26 and on the outer peripher with teeth adapted to engage theteeth of w eel 27. The sleeve 28 carries a `collar 29 which is connectedby means of a yoke 30 to a control shaft 31. The latter projects throughthe outer 'wall of the cylinder block and carries a control lever 32. Itwill be evident that by operating the lever 32 to slide the sleeve 28 onthe'shaft 2A, the posit-ion of the wheel 27 may be advanced or retardedangularly with respect to the wheel 26, without interfering with thewheel 27 by the Vwheel 26, or vice-versa, through the intermediaey ofthe toothed sleeve 28.

The wheel 27 is formed on its outer periphery with sprocket teethadapted toengage a chain belt 33 which passes about a sprocket wheel 34secured tothe crank shaft 21.A The diameter of the sprocket wheel 34 isone-half the diameter of the sprocket wheel 27 so that lthe crank shaft21 is geared to make two revolutions for each revolution of the crankshaft 24, and hence the'pistons 16 make two complete reciprocations foreach reciprocation of the pistons 18. Furthermore, in the particulardesign shown inthe drawings the length of the crank arms on the shaft 21is twice that of the crank arms on the shaft 24,

sothat the piston speed of the pistons 17 is four times that `ofthepistons 18. This .relation, however, is arbitrary and may be varied f indill'erent designs.

Immediately above the water jacket 19 the cylinder block is formed withVan intake manithe cross sectional view Fig.

fold 35, connected with a suitable earbureter 36. Ports 37 leadl fromtheintake manifold into the cylinder 16. These ports vare distributedabout each cylinder, as shown in A 4, so as to provide an intake ofbroad area for the admission of the fuel mixture.A At a point lower downon the cylinderr block and within the the driving of water jacket, thereis an exhaust manifold 38 connected with an exhaust pipe 39, and ports40 distributed around the cylinder, lead therethrough to connect thecylinder with the exhaust, as shown in the cross sectional view Fig. 5.The ports 37 and 40 are adapted to be controlled by the piston 18.

The construction of the piston 18 is shown clearly in Figs. 1 and 2. Itwill be observed that the intake mixture is fed into the interior ofpiston 18 through ports41 and is delivered to the cylinder, between thepistons 17 and 18, through a port 42 formed inthe bottom of the latterpiston. The port 42 is in the form of an elongated slot and isControlled by a hollow piston pin 43 which connects the rod 25 to thepiston 18. The hollow piston pin 43 thus serves as a valve and isarranged to oscillate in a bearing carried by the piston 18. The bearingis preferably formed of a lower semi-cylindrical section 44 'securedtothe bottom wall of the piston 18 and provided with a port thereinwhich registers with the port 42, and of an upper semicylindricalportion 45 provided with an extension 46 secured to the top of thepiston by means of a threaded ring 47. The extension 46 has a slottherein through which passes the connecting rod 25, the slot beingflared toward the top to provide freedom for angular movementof theconnecting rod.

Figs. 1 and 2 show the position of the pistons at the point of ignitionwhen set for full load, with a maximum combustion space between the twopistons. A port 48 is formed in'each cylinder to receive a spark plug49, by which the charge is tired. By moving the control lever 32 theposition of piston 18 with respect to piston 17 may be adjusted toreduce the combustion space as may he desired for various loads. At thesame time this adjustment varies the volume of fuel mixture to becompressed to said combustion space, as will be explained presently.

The lower piston 17 and its connection to the rod 22 are lubricated inthe usual inanner. To provide for lubricating the upper piston 18 andthe pin 43, I provide an oil pipe 50 by which oil is delivered underpressure to the bearings of the crank shaft 24, thence the oil finds itsway down to the piston 18 and through the slot in the extension 46 tothe pin 43.

As explained above, the piston 17 operates through a four-stroke cycleWhile the piston 18 operates through a two-stroke cycle. When the chargein the combustion chamber is red the pistons 17 and 18 are driven inopposite directions, thelatter piston operating at a lower Speed thanthe former piston, and both pistons deliver power to the crank shaft 21.The relative movement of the pistons will be understood by referring tothe shafts, respectively,lat variouspoints in the cycles of the twopistons when set Vfor operating at full load. It will be observedl thatthe position of the crank shaftA 24 may be adjusted through an angle ofdegrees with stood vby referring to the schematic views 8 to'.

12 inclusive.' In Fig. 8 the pistons are shown at the ignition point, atwhich point the lower crank is in vertical positionv or top center andthe piston 17 is at the top of itsstroke, while the upper crankhas-moved through an angle of 671/2 degrees frombottom center and hasraised the piston 18 part way up on its rising f stroke: In thisposition the exhaust ports Il() Aare closed and although the inlet ports37 are open to the interior of the piston 1 8, the pm 43 has closed themain inlet port 42. lWhen the charge is fired, it operates to'drive thelower piston downward andthe upper piston upward, thus delivering acertain portion of its power to the upper crank shaft 24, this powerbeing transmitted through the chain 33 to the crank shaft 21. Theexpansionperiod continues while the lower crank passes through an angleof 120 degrees and the u per' crank through, an angle of degrees, w en,as-shown in Fig. 9, the piston 18will begin I to uncover the exhaustports 40. The ex- 7 haust ports will remain open while the lower angleof 105 degrees, or 521/2- degrees past top.

crank is passing through a further angle of 210 degrees and theuppercrank through an center. This position is shown in Fig. 10,

, when it will be vobserved that the -exhaust ports 4Q are closedcompletely by the descending auxiliary piston. In the meantime, the

throw of the upper crank will have turned the pin 43 to such position asto 'open the port 42, but the-inlet ports 37 remain closed.

TheV next view Fig. 11 shows'the4 relation of the pistons after -thelower crank has passed through an Aangle of 60 degrees, or 80 degreespast -top center, duringwhich time the upper piston has descended untilthe ports37 begin 55) to open. Since the port 42h-as remained openduring this part ofthe cycle,a charge of fuel will now How into thiscylinder, being drawn Jin by suction of the receding lowerpiston.l Theintake ports 37 and 42remain open whilethe lower crankpasses through anangle of250 degrees, or 100 degrees past bottom center, -when the partswill assume the position Shown in Fig. 12 with the port42 just closedand the compression period just beginning. During the part of the cyclejust described, the charge full drawn into the cylinder by descent ofthe lower piston will be partly rejected as the piston rises and lwillbe forced back into theintake manifold; and so there is no attenuationof the fuel charge. in the Vcylinder at the beginning of the compressionperiod. During the compression period both pistonsmove upward,but thelower piston moves much morexrapidlythan the upper pistomso that thecharge is compressed between the two pistons untilvthey reach theposition shown in Fig. 8, when the charge is ignited and a new cyclestarts. As shown in the diagram Fig.

V7, the expansion stroke of the lower` piston is 120 degrees while thecompression stroke is degrees, and becausek the upper piston is recedingduring the` expansion period, the ratio of expansion to compression isleven greater. The point at whichcompression begins is so chosen that'the fuel charge will not be compressed to or above the critical pressurein the combustion space. i

W'hen operating at lighter loads a greater part of the fuel charge inthe cylinder is rejected by delaying the closing of the intakeportsuntil the lower piston has risen higher on its upward strokeand-dull compression -of this lighter 'charge isobtainedby reducing thecombustion space between the pistons.

This result is leffected by operating the control lever 3210' move thecrank shaft 24 counterclockwise, with respect to the crank shaft 21.Assuming that this relative setting has been etlectedthrough an angle of30 degrees, the relative positions 'of the pistons at correspondingpoints in the cycle will appear as indicated by dotted. lines in theFigs. .8 to 12v. Timing of ignition is controlled by the lower crankshaftv 21 in the usual manner, and since cra-nk shaft 24 has beenretarded 30 degrees with respect to crankshaft 21, the upper piston willhave risen very slightly, as shown by thedotted linein F ig. 8, whenignition takes place. In other words, rctarding of the upper crank shaftreduces the combustion space. The expansion stroke is also increased bythe fact that-the lower crankv shaft must move througha full 18.0degrees befor'ethe upper piston has risen far enough to uncover theexhaust ports. The exhaust stroke will continue whilethe lower pistonrises to the top of its stroke and begins to recede before the exhaustports will be closed. v Intake will begin with the top ofthe lowerpiston at the dotted line in Fig. 11-and the intake ports will' 'remainopen while the lower piston is moving down to draw in thecharge andmoving up again to reject a part of the charge'. Compression of thecharge will not begin until the lower piston has ,risen to the dottedline position shown in Fig. 12. Thus at low'loads a much smaller volumeoffu'el mixture is measured olf by the relative movement of the j n twocpistons', but this is compressed t0 the egreeof pressure beforeignition by the relatively closer approach of the two pistons,

as indicated by the dotted line position of the auxiliary piston in Fig.8.

Thus I have provided for variations in combustion space and variation infuel ehargevolume for different loads, both variations being effected bymovement of a single control lever 32. My motor does not require the useof a throttle lever, as full control is afforded by the lever 32.However, it will be, obvious that I could use a throttle to control theintake manifold whenever desirable or necessary to meet specialconditions. ln addition to providing for uniform compression, I haveprovided for a material increase in the ratio oferpansion tocompression, particularly in the case of light loads, so that thethermal elieiency' of my motor may be actually higher at light loadsthan at heavyv loads. This is of particular' import-ance in automobileservice in which motors are normally run at about a quarter of fullload. In such service a marked economy in fuel consumption will be shownby my improved motor.

A number of mechanical advantages are tobe found in the port controlprovided by my invention. Itmfill be observed that the oscillating pin48 has a slow angular movement while the piston 18 is moving rapidly,and a rapid angular movement while the piston is moving slowly. Thus theoscillating pin has but slight motion when it is under the greatestpressure, and the piston 18 opens the ports`37 rapidly at the beginningof the i' intake period. .The oscillating pin is subjected to greatestpressure during the expansion stroke or while `the parts are moving fromthe position shown in Fig. 8 to that.'

shown in F ig. 9. During this period there is but slight angularmovement of the oscil* lating pin, while at the same time the piston 18is rising rapidly under the impulse of the burning fuel. During theexhaust period and while the oscillating pin is under little pressure,it turns rapidly to open the port 42, as shown in Fig. 10, andthereafter hasbut slight movement while the piston 18 is mov; ingdownward rapidly to the positionshown in Fig. 11, when the inlet ports37 are opened. Finally, the oscillating pin turns rapidl to close' theport 42 and begin the compression period, 'as shown in Fig'. 12. Owingto this rapid opening of the intake ports 37, there is no throttling orchoking action tending to retard the iiow of the fuel mixtureinto theworking cylinder, and the quick closing of the Iport 42 clearly delinesthe beginning of the compression period.

It is also to be noted that the pin 43 and the lower bearing or seat 44are pressed together practically all of the time and particularly whenpin 43 is functioning to con-` trol the intake. Thus/at the moment ofigl nition there is an upward compression pressure/'of the piston 18 andseat 44 against the pin 43, servinfr'to keep the pin sented and preventleakage back into the intake manifold. This pressure is continued duringthe expansion stroke, and during the exhaust period the rising piston 17exerts a slight upward pressure against the piston 18, holding the seatagainst the pin 43 while the latter is opening thegport 42. During theirst part of the intake period, the crank shaft 24 resses the pin 43against the seat 44, and on t 1e upward stroke of the piston 17 justprior to the beginning of the compression period, there is an upwardpressure against the piston 18 serving to seat the pin 43 snugly, whilethe pin is closing the port 42. Thus there is never any knocking of thepin 43 in its bearing and considerable wear could take place between thepin 43 and its seat 44 without interfering in the least with thesuccessful operation of the motor because the pin is always firmlyseated when called upon to control the intake. By making the bearing forpin 43 in two semicylindrical sections, the upper one of which may beforced downward by means of the threaded ring 47, I provide for takingup slack between the pin 43 and the lower section or seat 44, when thewear becomes excessive.

It will be noted that my improved motor is valveless, in the same sensethat any ordinary two-cycle motor is valveless. ln other words, I do notuse any inert auxiliary parts to control the ports. No power is wastedin moving valves against springpressure or gas pressure to open theports, and no inert sleeve members are employed to control the ports.Instead I use a working piston to control the intake and exhaust by itsposition in relation to the cylinder and in relation to the piston pin.In the latter respect my control of the intake differs' from theordinary two cyclo motor, for I pass the intake mixture through thepiston 18. Furthermore, the cool fuel mixture flows back and forththrough the piston during a part of each cycle and serves to keep downthe temperature of the piston pin 42. It will be realized that this is avery important feature of my invention.

The upper portion of my motor is not to be considered merely as a valvegear, but should f be recognized as a power delivering part ofthe-motor. In the particular design shown, the four-stroke pistondelivers the greater part of the power,`but my invention is not limitedto this particular design. It will be evident that the parts could he soproportioned that the two-cycle pistons would deliver more power thanthe four-cycle pistons, or that they could both deliver equal power.There are marked advantages in delivering vequal power'to the two crankshafts, particularly in aeronauticserviee, in which it is commonpractice to provide two speeds, one of which is twice'the speed of theother, and, with my engine, such variation of speed could readily beobtained by direct coupling to one with theunderstanding that variouschanges,

alterations and modiiications may be made in the construction andarrangement of my motor without departing from the spirit and scope ofmy invention. v v i l claim: l. In an internal combustion motor, acylinder, a pair oi pistons reciprocabletherein and cooperating toprovide a' combustion' space therebetween, a power' shaft operativelyconnected to said pistons, said pistons being arranged to movesimultaneously in oppositedirections under the impulse of eachexplosion" in the combustion space and each piston delivering power tothe power shaft, the cylinder being formed'with intake-and exhaustports, and one of said pistons providing sole control for the openingand closing of saidports, and means for varying the relative timing ofsaid pistons to vary the volume of said combustion space.

2. In `an internal combustion motor, a cyl-- inder, a pair of pistonsreciprocable therein, said pistons cooprating to provide a combus tionspace there t atively. connected tosaid pistons, o e of aid pistonsbeing adapted to operate n a fourstroke cycle-and the other on atwo-stroke] cycle and each piston delivering power tothe power/shaft,the cylinder being formed with intake and exhaust ports, the two-strokepiston providing sole control for the opening and closing of said ports,and mearis for varying 4 the relative timing of saidpistons to vary thevolume of said combustion space.

3. In an internal combustion motor, acylin- .'der, a pair rof pistonsreciprocable therein,

said pistons cooperating to provide a combustion space therebetween, apower shaftfop'enaf tively vconnected-to said pistons, one of saidpistons being adapted to operate on a fourstroke cycle and the other on-,a two-stroke cycle and'eacli vpiston delivering ower to the power.shaft, the cylinder being orined with intake and exhaust ports, thetwo-stroke pis# ton providing sole control the opening land closing ofsaid ports, and means for varying the relative timing of said pistonstolvary the volume of said combustionspace and the vol inne of the f uelcharge retained in the cylinder. A 4. -In an internal combustionmotor,-a cyltween, apower shaft o erinder, a piston reciprocabletherein, a crank shaft, a connecting rod carried by the crank shaft, anda hollow piston pin secured to the connecting rod and 'journaled tooscillate in the piston, the piston being formed with a fuel plassageleading therethrough and throng said piston pin, the latter serving byoscillatory movement theroto open and close saidinel passage.

5. In an internal combustion motor, a cylinder having a working chamber,a hollow pistonA reciprocable in the cylinder, a hollow piston pin journaled in the piston and com municatingwith the interior thereof, acrank shaft, and a connecting rod pivotally connected at one end to anarm of the crank shaft and secured at the other end to the pis ton pin,the cylinder andthe piston being formed with ports coacting periodicallyto ,open communication with the interior oi' the piston, the pistonbeing also formed with a passage leading from the journal of the pistoninto the working chamber of the cylinder, and the piston pinbeing'provided with a Vport vcooperating upon' oscillatory more ment ofthe pin during rciprocation of the Vpiston to periodically opensaidpassage.

6. In an internal combustion motor, a cylinder having a Vworking chamberand formed with an exhaust port openingv out of said` chamber, a pistonformed with a fuel chamber therein and reciprocable in the cylinder,said piston being adapted to open and;` close said exhaust port, saidcylinder and piston being formed with inletports 'adapted periodic'allto .establish communication with said fuel c lamber, a hollow piston pinjournaled in the piston and openI to said fuel chamber, a crank shaft,and a connecting rod pivotally connected at one end to an arm of thecrank shaft and secured at the otheren d to thepiston pin, the pistonbeing formed 'with a passage leading from the journal of the piston intothe working chamber, the piston pin beingformed with a port adaptedupon. oscillatory movement of the pin during reciprocation oit thepiston to open said passage periodically to the interior of the piston.

- 7. In an internal combustionmotor, apair of crankshafts, a pair ofintermeshingspirally toothed wheels driven by saidV crankshaftsrespectively, andmeans for effecting relative axial movement ofl saidwheels to advance one crankshaftangularly with respect to the4 8. In aninternal combustion motor, a pair of .cx-ankshafts,V -a spli'rallyvtoothed wheel driven' by onecranks aft, a second spirally i toothedwheeldriven by the other crankshaft,

a toothedidler engaging the said wheels, and means for sliding the idleraxially to advance one crankshaft a gularly with respect to the other. z.1'

9. In an internal combustion motor, a .pair of crank shafts, a spin-allytoothed wheel driven by one shaft, a second wheel concentric with thefirstwheel and driven by the other shaft, the second wheel being:rformed with internal spiral teeth reversely pitched with respect to theteeth of the first wheel, a sleeve slidable between said wheels andformed with external and internal spiral teeth engaging the teeth ofsaid wheels, and means for sliding the sleeve axially to advance onecrank shaft angularly with respect to the other.

, l0. In an internal combustion motor a plu` rality of cylinders eachformed with a fuel port, a manifold adapted -to supply fuel to thecylinders through said fuel ports, a pair of power-deliveringpistonsreciprocable in each cylinder inrelatively timed relation, one of saidpistons in each cylinder being formed ywith a fuel passage adaptedperiodically to communicate with the fuel port whereby on relativemovement of the two pistons a charge of fuel will first be drawn intothe cylinderand a part of the charge will then be returned to themanifold, means for closing the passage to retain a predetermined amountof fuel in the cylinder, and means for communicate with the fuel portwhereby on relative movement of the two pistons a charge of fuel willfirst be drawn into the cylinder and a part of the charge will then bereturned to the manifold,-means for closing the passage to retain apredetermined amount of fuel in the cylinder, and means for varying therelative timingr of the two pistons to vary the amount of fuel retainedin the cylinder and vary the volume of said combustion spaceproportionately to the amount of fuel retained so as to preserve uniformcompression of fuel in the combustion space.

l2. In an internalcombustion motor, a ycylinder providing a workingchamber and formed witha fuel port, a hollow piston reciprocable in thechamber, the pistonbeing formed with a lateral port adapted upon thereciprocation of the piston to alternately open and close the fuel port,the piston being also formed with a bottoni port leading;r into theworking chamber, a crank shaft, a connecting rod carried thereby, ahollow piston pin secured to the connecting rod and journalled in thepiston in open communication with the hollow interior thereof, thepiston pin being formed with a port adapted to register with said bottomport at certain predetermined angular positions ofthe crank shaftwhereby the bottom port will be opened before eachopening of the lateralport and closed before each closure of the lateral port.

Signed at New York, in the county of New York and State of New York,this 4th day of January, A. D. 1927.

MILAN lV. HALL.

